Ferrography
deals only with ferrous (metallic) byproducts that are suspended in oil.
Here a technician places a sample of oil on a slide and subjects it to
a magnetic field. He or she can then look at the size of the deposits
and determine if the results are within acceptable limits.

Once a lab has conducted
all three tests, a technician will correlate the results and interpret
them for you, usually providing a detailed report that includes specific
(and easy-to-understand) explanations and remedies. That can be invaluable,
especially if you happen to be buying a used boat. But unless you’re
looking for specific engine problems, the key to getting the most out
of oil analysis is to establish wear and contamination trends, and the
best way to do that is by having your oil analyzed on a regular basis—usually
at the start and end of each boating season. The process is quick: Spectrographic
analysis of a single oil sample typically takes about a minute, and you
needn’t bring the sample to the lab. Most places will let you send
in a sample by mail, and you’ll probably have your results back within
a week.

Many test labs will
give you a disposable tube for collecting an oil sample from your engine,
plus the bottle to put the oil in and a mailer for the bottle. And many
engine companies offer quick-connect fittings to attach to your engine
to make the process even easier. That’s important for reasons beyond
convenience, because whichever method you use, cleanliness is of the utmost
importance. Anything that gets into the oil after it leaves the engine—grease
from the engine exterior or a rag, or even oil from your hands—can
cause erroneous analysis results. Best of all, the cost for all this is
moderate, ranging anywhere from $12 for a simple test to around $60 for
a complete analysis.

Oil analysis is available
from a variety of sources, including laboratories (look in the Yellow
Pages under “Laboratories, spectrographic analysis”), engine
manufacturers, and engine distributors and dealers. Most Caterpillar distributors
offer Scheduled Oil Sampling (“S-O-S”), which is designed to
encourage boaters to set up long-term programs for their boats, and the
system works even if you don’t have a Caterpillar diesel. (Most other
distributors have similar programs.) These Cat distributors sell sampling
kits that include instructions, a pump for removing the properly sized
oil sample through a dipstick hole, and ten containers with prepaid mailers
for around $120. And remember that oil analysis works well on gasoline
engines and marine gears, too.

Crude oil may be an
amazing substance, but in its own way, oil analysis is just as remarkable.
What else can you name that is so easy, inexpensive, and informative and
can make your boating experience trouble-free?